package com.hmdp.service.impl;

import com.hmdp.dto.Result;
import com.hmdp.entity.SeckillVoucher;
import com.hmdp.entity.VoucherOrder;
import com.hmdp.mapper.VoucherOrderMapper;
import com.hmdp.service.ISeckillVoucherService;
import com.hmdp.service.IVoucherOrderService;
import com.baomidou.mybatisplus.extension.service.impl.ServiceImpl;
import com.hmdp.utils.RedisIdWorker;
import com.hmdp.utils.SimpleRedisLock;
import com.hmdp.utils.UserHolder;
import org.springframework.aop.framework.AopContext;
import org.springframework.data.redis.core.StringRedisTemplate;
import org.springframework.stereotype.Service;
import org.springframework.transaction.annotation.Transactional;

import javax.annotation.Resource;
import java.time.LocalDateTime;

/**
 * <p>
 *  服务实现类
 * </p>
 *
 * @author 虎哥
 * @since 2021-12-22
 */
@Service
public class VoucherOrderServiceImpl extends ServiceImpl<VoucherOrderMapper, VoucherOrder> implements IVoucherOrderService {

    @Resource
    private ISeckillVoucherService seckillVoucherService;

    @Resource
    private RedisIdWorker redisIdWorker;

    @Resource
    private StringRedisTemplate stringRedisTemplate;


    /**
     * 秒杀优惠券
     * @param voucherId 优惠券id
     * @return 订单id
     */
    @Override
    public Result seckillVoucher(Long voucherId) {
        //1.查询优惠卷
        SeckillVoucher voucher = seckillVoucherService.getById(voucherId);
        //2.判断秒杀是否已经开始
        if (voucher.getBeginTime().isAfter(LocalDateTime.now())) {
            //尚未开始
            return Result.fail("秒杀尚未开始!");
        }
        //3.判断秒杀是否结束
        if (voucher.getEndTime().isBefore(LocalDateTime.now())) {
            //尚未开始
            return Result.fail("秒杀已经开始!");
        }
        //4.判断库存是否充足
        if (voucher.getStock()<1) {
            //库存不足
            return Result.fail("库存不足！");
        }

        //7.返回订单号
        Long userId = UserHolder.getUser().getId();
        //创建锁对象
        SimpleRedisLock lock = new SimpleRedisLock("order" + userId, stringRedisTemplate);
        //获取锁
        boolean isLock = lock.tryLock(1200);
        //判断是否获取锁成功
        if (!isLock) {
            //获取锁失败，返回错误信息
            return Result.fail("不允许重复下单!");
        }

        //获取代理对象（事务）
        try {
            IVoucherOrderService proxy = (IVoucherOrderService) AopContext.currentProxy();
            return  proxy.createVoucherOrder(voucherId);
        } finally {
            //释放锁
            lock.unLock();
        }

    }

    @Transactional
    public Result createVoucherOrder(Long voucherId){
            //6.一人一单
            Long userId = UserHolder.getUser().getId();
            //查询订单
            int count = query().eq("user_id", userId).eq("voucher_id", voucherId).count();
            //判断是否存在
            if (count > 0) {
                //用户已经购买过
                return Result.fail("用户已经购买过一次！");
            }

            //5.扣减库存
            boolean success = seckillVoucherService
                    .update().setSql("stock = stock - 1")// set
                    .eq("voucher_id", voucherId).eq("stock", 0)// where
                    .update();
            if (!success) {
                return Result.fail("库存不足！");
            }


            //6.创建订单
            VoucherOrder order = new VoucherOrder();
            //订单id
            long orderId = redisIdWorker.nextId("order");
            order.setId(orderId);
            //用户id

            order.setUserId(userId);
            //代金券id
            order.setVoucherId(voucherId);
            save(order);

            //返回订单id
            return Result.ok(orderId);

    }
}
